Means to hold an electric switch spindle in different axial positions



Patented Dec. 13, 1949 MEANS TO HOLD AN ELECTRIC SWITCH SPINDLE IN DIFFERENT AXIAL PO SITIONS David W. Johnson, New Britain, Conn., assignor to The Arrow-Hart &.Hegeman Electric Company, Hartford, Conn., a corporation of Connecticut Application September 20, 1946, Serial No. 698,153

This invention relates to means for holding an electric switch spindle in different axial positions,

and more particularly to means for that purpose which will allow the shaft or spindle to be moved axially to and from its several positions.

For the aforesaid purpose it has heretofore" been a common practice to have ball bearings backed up by coiled springs which press the balls 14 Claims. (Cl. 74527) into indentations in the spindle. Such structure takes up a considerable amount of space. Also, the seating of the spring upon the ball tends to retard its rotation, which in turn causes wear on the high point between the indentations in the spindle.

Another disadvantage of the spring and ball type of holding means is that when the spindle is removed for any reason, the ball and springs will fall into the switch mechanism, from which they can be retrieved, in many cases, only .with considupon the amount of movement of the shaft, it is necessary to use large balls and at the same time heavier and deeper springs, which require much more space than the requirement for economical design would normally permit in an efficient and compact switch structure.

One object of my invention is to provide an economical, sturdy and reliable spindle locating means for an electrical switch which may be economically manufactured and easily assembled Figure 4 is an end elevation view of the structure illustrated in Figure 3;

Figure 5 is a side elevation view of a modified form of the invention; while Figure 6 is a plan View of the spring and roller supporting bracket used in the form of invention illustrated in Figure 5.

Referring to the drawings, the invention is illustrated in Fig. 1 as being mounted in .a hollow switch base H) of insulating material having a recess l2 in which is located the means for pcsitioning the spindle or shaft M of the switch. For the purpose of illustration, stationary contacts l6, of conventional form, are shown as being bridged by a movable contact [8, also of conventional form which is mounted upon the end of the switch spindle l4 in any convenient or suitable fashion.

Upon the switch spindle, at any suitable point,

are formed two or more cylindrical grooves and thereof, a pair of cylindrical rollers 24 and 26,

which are rotatablymounlted upon parallel extension or extending ends and 32 of a coiled spring 34. The spring and rollers are mounted upon and supported by a U-shaped frame or bracket stamped conveniently from sheet metal.

, The frame or bracket 40 has parallel side plates and which will not possess the disadvantages of I the spring-and-ball type of spindle locating means. 7 Another object of my invention is to provide a spindle locating means for electric switches which can be assembled and removed as aunit in electric switch structures.

Another object of my inventionist'o provide a. novel form of spindle locating means having simplified structure for supporting the holding members requiring a less number of springs than herethe parts of the unit in the position they occupy 7 when the spindle is passing from one axial position to another;

4 2 and 44, the plate 44 having slots 46 in alignment extending in from opposite edges thereof ito receive the end portions of the spring extensions 30 and 32 and topermit those ends to have limited lateral movement. In the plate 42 there are a pair of elongated apertures 48, through which pass the inner portions of the spring extensions and allowing only limited lateral move- 'ment thereof. Between the parallel side plates 42 and 44 and on the mid-portions of the spring extensions are mounted the rollers 24 and 26. These mid portions thus afford axles on which the rollers may rotate.

The coil portion 34 of the spring tends at all times to expand. This causes the points 20' on the extending spring ends to press against the outer ends of the elongated apertures 48 so that those outer ends provide fulcrum points. Thus the axle portions exert a constant pressure toward the shaft I4 and press the rollers into the grooves 20 and 22.

Although the foregoing is preferred, it is within the scope of my invention to use a spring whose the ends of the spring extensions may engage the side of the holes 48 and fulcrum thereabout.

From the foregoing it may be seen that the different axial positions comprising roller means engageable in one or another of said grooves, spring means having a portion affording an axle for said roller means, said spring having a coiled portion and an extending end portion affording an axle for said roller means, said axle portion exerting a constant pressure toward said shaft, a bracket affording a support for said spring having parallel side plates through which said extending portion of the spring passes, the coiled portion of said spring being outside said bracket, and means on said bracket extending beyond said coiled portion and engaging the back of said coiled portion to hold said spring in assembly upon said bracket.

6. In combination with an axially movable shaft having axially spaced indentations thereon, the means for locating said shaft in different axial positions comprising roller means engageable in one or another of said indentations, spring means having a portion affording an axle for said roller means, and means providing a fulcrum point for a portion of said spring to cause said axle portion to exert a constant pressure toward said shaft.

'7. In combination with an axially movable shaft having circumferential grooves axially spaced thereon, the means for locating said shaft in different axial positions comprising substantially cylindrical roller means engageable in one or another of said grooves, spring means having a portion affording an axle for said roller means,

and means providing a fulcrum point for a portion of said spring to cause said axle portion to exert a constant pressure toward said shaft.

8. In combination with an axially movable shaft having axially spaced indentations thereon, the means for locating said shaft in different axial positions comprising a pair of rollers engageable in one or another of said indentations, spring means having extending ends affording axles for said rollers, and means providing fulcrum points engaging said extending spring ends to cause said axle portions to exert constant pressure toward said shaft in opposite directions.

9. In combination with an axially movable shaft having axially spaced indentations thereon, the means for locating said shaft in different axial positions comprising roller means engageable in one or another of said indentations, spring means having a portion affording an axle for said roller means, and a bracket member on which said spring and roller means are mounted to enable assembly and removal of said locating means as a unit, said bracket member having fulcrum points engaging said spring adjacent said axle portion to cause said axle portion to exert a constant pressure toward said shaft.

10. In combination with an axially movable shaft having axially spaced indentations thereon, the means for locating said shaft in different axial positions comprising a pair of rollers engageable in one or another of said indentations, spring means have extending ends affording axles for said rollers, and a bracket member on which said spring and roller means are mounted to enable assembly and removal of said locating means as a unit, said bracket member having fulcrum points engaging said extending ends to cause said axle portions to exert constant pressure in opposite directions toward said shaft.

11. In combination with an axially movable shaft having axially spaced indentations thereon, the means for locating said shaft in different axial positions comprising a pair of rollers engageable in one or another of said indentations, spring means having extending ends affording axles for said rollers, and a bracket having portions through which the spring ends extend and between which said rollers are located, certain of said bracket portions providing fulcrum points for said extending ends to cause said axle portions to exert constant pressure in opposite directions toward said shaft.

12. In combination with an axially movable shaft having axially spaced indentations thereon, the means for locating said shaft in different axial positions comprising a pair of substantially cylindrical rollers engageable in one or another of said indentations, a coiled spring having end extensions extending on opposite sides of said shaft and affording axles for mounting said roller means, and a bracket having parallel arms through which pass said spring extensions and between which said roller means are located to enable assembly and removal of said locating means as a unit, one of said arms providing fulcrum points for said sprin extensions to cause said axle portions to exert a constant pressure in opposite directions toward said shaft.

13. In combination with an axially movable shaft having axially spaced indentations thereon, the means for locating said shaft in different axial positions comprising roller means engageable in one or another of said indentations, spring means having a portion passing through and affording an axle for said roller means, said axle portion exerting a constant pressure toward said shaft, a bracket member on which said spring and roller means are mounted to enable assembly and removal of said locating means as a unit, said spring being a coiled spring and said brackets having means thereon engagin the coiled portion of said spring to hold said spring on said bracket.

14. In combination with an axially movable shaft having axially spaced indentations thereon, the means for locating said shaft in different axial positions comprising a pair of rollers engageable in one or another of said indentations, spring means having extending ends affording axles for said rollers, said axle portions exerting constant pressure in opposite directions toward said shaft, a bracket member on which said spring and roller means are mounted to enable assembly and removal of said locating means as a unit, said spring being a coiled spring and said bracket havin an extension engaging the coiled portion of the spring to hold said spring on the bracket.

DAVID W. JOHNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 813,921 Shepard Feb. 27, 1906 1,212,346 Hall Jan. 16, 1917 1,276,926 Jensen Aug. 27, 1918 2,085,904 Freese July 6, 1937 2,107,463 Woltersdorf Feb. 8, 1938 2,115,284 Pratt Apr. 26, 1938 

